In this task, you are given a context and four options. Each option is a suggested ending for the context. You should read the context and pick the best ending for the context. Please answer with "A", "B", "C", and "D". 

[header] How to replace a door sill [title] Measure the existing door threshold for length and width. [title] Purchase a metal sill of the same size and shape. [title] Use a variable speed drill fitted with a screwdriver bit to remove the screws anchoring the threshold into place. <sep> (A) [title] Sand away any rough patches by hand using 300 grit sandpaper. [title] Straighten out any jagged edges of the existing surface by spreading the screws over them. (B) [title] Use a utility knife to cut through any caulk on the front and back edges of the sill. [title] Place the end of a pry bar beneath the threshold and pull up on the bar to pull the old threshold away from the door frame. (C) [title] Drill a hole through the square perimeter. [title] Use a reciprocating saw to cut around the perimeter of the sill and door frame. (D) [title] Punch 4 holes in the sill in between the pins on the outside of the frame , [substeps] Use a reciprocating drill to punch 4 holes to the frame of the door. Make sure that each hole is drilled evenly on both sides, allowing for a 5/2 " gap between the holes.
B